Squeezing device for plastic and semplastic masses



z- 1942- s. KIESSKALT ETAL 2,293,297

SQUEEZ'ING DEVICE FOR PLASTIC AND SEMIPLASTIC MASSES Filed April 3, 1939- 3 Sheets-Sheet l MEQFMED KtESSKALT KARL M H H AcKER KKK L E R8 INVENTORS B! 44:3 AL

ATTORNEYS.

3.8;1942- s. KIESSKALT ETAL 2,293,297

SQUEBZING DEVICE FOR PLASTIC AND SEMIPLA'STIC MASSES Filed April '3, 1939 :s Sheets-Sheet 2 SI E oFRU-I \usss mu KARL wmNAcKER KARL. E R a mvsmoas ATTORNEYS.

S. KIESSKALT ETAL SQUEEZING DEVICE FOR PLASTIC AND SEMIPLAS'I'IC MASSES Filed April 3, 1939 s Shsets-Sheet s Knessmur NAc eR V VENTORS ATTORNEYS.

Patented Aug. 18, 1942 sounnzmo nrzvrcn FOR rms'rrc Arm samrmsrrc MASSES Siegfried Klesskalt,

Karl Winnacker, and Karl Erb, Frankfort-on-the-Main, Germany, use! ors, by meme assignments, to Walther H. Duisberg, New York, N. Y.

Application In April 8, 1939, Serial No. 265,750 Germany April 9, 1938 15 Claims. (Cl. 100-48) The present invention relates to a squeezing device for plastic and semi-plastic masses.

For the purpose of mechanically squeezing water from the coagulates of caoutchouc, synthetic caoutchoucor plastics, oil or micella from seeds or water and extracting agents from pastes of coal and oil and soon, there are generally used strainer presses or worm presses. Both types of press have the same characteristic feature, namely thatthe material to be pressed is caused to travel along the strainers and cage-sieves under heavy pressure, and is, furthermore, solidified in the sieves. The speed of the press is low, the friction is high and the out-put per unit surface of the sieves is rather small.

This invention relates to a squeezing apparatus which comprises a combination of rotating worms or spindles with broad threads and has elongated channels provided for the material to be squeezed, which passages constantly change in cross section, whereby the contact surfaces mainly move towards each other. The space serving for the exit of the liquid is formed by the parts of the apparatus themselves and extends along their entire efiective length. According to the invention these features are afiorded by a rotating inner main worm withbroad threads which closely 'intermeshes with several outer worms, each of them having the same breadth of thread and the same pitch as the inner worm, and further by closing the wedge-shaped spaces beiacent ribs which are provided with plain edges at the side turned towards the inner worm. The inner worm and the outer worms may be singleor multi-threaded; the .number of threads and the diameter of one of the two intermeshing worms, preferably the inner worm may be a multiple by a whole number of-threads and the diameter of the other worm. The outer worms may be similar to each other, but the number and the diameter of several outer worms may be diiferent. The worms may be rotatably mounted tosupports'rigidly conne ted with the ribs, one of the supports'being provided with an inlet and the other one with an outlet; the latter may further be provided with an adjustable throttling device.

In this apparatus the material is intensely treated while the liquid to be expressed separates near the large moving surfaces and escapes through the spaces along the sides of the worms, under the effect of the shearing force and the excess pressure in the channel. Thewidth oi the passage formed by these spaces is only limited by the necessary mechanical play for the operating parts and the accuracy of workmanship; .the width of the passage may. therefore, be much smaller than has hitherto been adopted for sieves and slotted strainers, though the new apparatus is more stable and of a simpler and less ex pensive construction than are the known apparatus.

The breadth of the threads of the inner worm may remain the same along the entire length 01'.

the worm. Alternatively the threads of the inner worm may widen in the direction of the movement of the material, and those of the outer worms narrow in the same direction; thus an ad- 15 tween the inner and outer worms by closely additional pressure is applied to the material during the movement of the inner worm.

The fundamental construction and the mode of operation of the new apparatus is illustrated in Figs.1 and 2 of the accompanying drawings, the breadth of the threads of all the worms being the same. Fig. 1 is a longitudinal section showing the intermeshing worms; Fig. 2 is a crosssection. Figs. 3 and 4 show the construction of a-similar apparatus in which the threads of the worms vary in breadth in the direction of the movement of the material.

In Figs. 1 and 2a double threaded inner worm A with a constant pitch and an invariable profile of the threads, is surrounded by six singlethreaded worms B similar to each other and of half the diameter of the worm A; the flanks of all I the worms thus have the same pitch line so that the worms move together freely. ,In wedgeshaped spaces between the outer worms B and the cylindrical outer surface of the main worm A ribs 0 are mounted which are sufliciently rigid to bending; such ribs may alternatively form part of a casing surrounding at a certain distance the entire system of worms.

In the apparatus illustrated only the two chan-,

. ribs C. The material to be treated enters, if

necessary under pressure, through the inlet E, fills the channels G and leaves the apparatus by way of the outlet F, as indicated in Fig. 1. The outlet F may, if necessary, be provided with an adjustable throttling device, in the simplest way by giving the outlet F a conical form with a steep inclination; the apparatus may, however,be pro- 55 vided with other known throttling devices, such as screws, slides or baflies. The flanks of the curved surfaces intermeshing with each other on .the inner worm and outer worms have to be profiled according to the rules of construction of capsule pumps so that they form only the desired passage. The liquid expressed through the passages formed by the helical and cylindrical surfaces of the worms runs off freely along the ribs C, except when the apparatus is surrounded by a casing as is desirable if loss of liquid is to be avoided. If such acasing is used an unchecked discharge of the liquid from the outer worms must be guaranteed.

The apparatus illustrated in Figs. 1 and 2 shows a further characteristic feature. The

depth of the threads of the inner and outer worms. may fundamentally be the same, as in the case of a capsule-oil-pump having several worms. In fact, this construction would for the present purpose have the advantage of exerting suction. It would, however, involve the drawback that the whole mass would be passed through the chambers without being thoroughly worked; the volume worked would not be sufficiently large.

p The drawback is avoided as indicated in Figs. 1 and 2 by profiling the threads of the inner worm so that they closely intermesh only so far as they are in gear with the threads of the outer worms, while in dependence upon the conditions of conveyance the depth of the profiled space between the threads of the inner worm is greater by the amount X than the height of the threads of the intermeshing part of the outer worms. When the apparatus is charged under pressure the above expedient allows an increased throughput of the apparatus of given dimensions; also a more effective treatment of the material as a result of frequent change in the cross-section of the channels as the surfaces of the worms roll upon each other and, above all, the transmission and distribution of the counter-pressure throughout the channels as the volume changes therein, this counter-pressure being. produced by the throttling at the outlet F.

In order to ensure that the material is pressed through the thread of the inner worm under the necessary pressure, this worm may be extended beyond the outer worms towards the inlet of the apparatus, the extension being surrounded by a suitable casing which, if necessary, is preferably internally profiled. The apparatus of the invention may be combined with kneading pumps or screws pumps in an arrangement in which individual parts of the whole structure are used in common for the charging pump and the new squeezing device.

When the squeezing apparatus is used for treating greasy goods, it suffices to operate only one of the worms, preferably the inner worm; the outer worms then automatically operate at the same time. In the case-of goods that are not greasy it may, however, be more suitable, to couple the inner worm with the outer worms by means of cog wheels.

The squeezing apparatus may also be constructed so that it exerts suction and has, without application of throttling devices, a compressing effect on the mass owing to the varying volume of the chambers which decreases from the inlet to the outlet; the liquid is thus expressed. Such a construction of the apparatus is shown in Figs. 3 and 4, in which there are used worms having decreasing threads cut in the form described in U. S. Patent No. 2,136,264

and intermeshing as in the case of the device described in U. S. Patent No. 2,115,006.

In Figs. 3 and 4, for instance, an irmer worm H intermeshes with 4 outer worms K. each of the latter having the same diameter which is also the diameter of the inner worm; the inner worm is, therefore, in this case only singlethreaded. The depth of the thread M of the inner worm is narrow at the inlet and increases towards the outlet, the pitch remaining constant; the depth of the threads N of the outer worms K decreases from the inlet to the outlet end. The plan Fig. 4 shows that in its construction this apparatus resembles that shown in Figs. 1 and 2. From a normal kneading pump it is principally differentiated by the fact that only the passage formed by the thread round the inner worm which is closed by the outer worms and the intermediate ribs, allows travel of the material, whereas the side worms remain open so that the expressed liquid may run off. In contrast with the kneading pump described in U. S. Patent No. 2,115,006, not the mass itself is pressed in this case through the flanks of the threads of the one worm into those of the other worms, but only foreign substances contained in the mass to be kneaded are passed through the threads. Therefore, the worms are out so that the dimensions of the chamber near the end of the inner worm are not decreased to come to a dead end, i. e. that even near this end there is still a certain distance between two adjacent threads of the inner worm.

In Fig. 3 the decrease of the passage volume is exaggerated for the sake of clearness; in practice such a decrease never occurs, unless, indeed, spongy. material is treated. In principle the compression is calculated according to the decrease of the volume to be expected.

In Figs. 3 and 4 there is also shown a ring P acting as a hoop surrounding the outer worms K and automatically rotating with the same speed as that of these outer worms. This ring serves as a support for the outer worms in order that the latter may not bend when heavy masses under high pressure are treated. In this manner a simple roller-support is provided operating with very little frictional loss; said roller-support relieves the slide bearings. In this case at least one of the worms, preferably the inner worm is driven and drives the remaining worms; if, however, the outer worms are tightly embraced by the hoop it is possible to drive the outer worms by means of this hoop, the inner worm being automatically driven by them.

All parts of the apparatus may be constructed for being heated or cooled, or for introducing liquid treating agents, for instance washing liquors, into the centre, for instance through the ribs situated between the worms or through an axial bore in the inner worm.

We claim:

1. A device for expressing liquid from liquidcontaining plastic material, comprising a central rotatable threaded worm, a plurality of rotatable, threaded, outer worms parallel and intermeshing with said central worm and circumferentially spaced from one another about said central worm, a fixed member mounted in each of the circumferential spaces between each pair of adjacent outer worms. each such fixed member being spaced from the other such fixed members and slidably engaging peripheral portions of the central worm and of a pair of adjacent outer worms, inlet means at one end of the central aasaaor worm for admitting material into the recessed peripheral portion of said central worm, and outlet meanswat the other end or said central with central worm and circum'ierentially spaced from one another about said central worm,

worm/said fixed members and outer worms cothe solid constituents of the worked material.

2. A device for expressing liquid from liquidcontaining plastic material. comprising a central rotatable threaded worm, a plurality oi rotatable, threaded, outer worms parallel and intermeshing with said central worm and circumferentially spaced from one another about said central worm,

a fixed member mounted in each of the circumierential spaces between each pair of adjacent outer worms, each such fixed member being spaced from the other such fixed members and slidably engaging p ripheral portions or the central worm and of a pair of adjacent outer worms, said worms being rotatably mounted on supports rigidly connected with said fixed members. inlet 'means at one end of the central worm for admitting material into the recessed peripheral portion of said centralworm, and outlet means at the other end of said central worm. said fixed members and outer worms cooperating with said central worm to form enclosed spaces in which the worked material is carried and compressed by the rotation of said worms, the working clearancebetween adjacent surfaces of said worms and members being arranged to provide restricted passages through which expressed liquid may pass outwardly from said spaces to efl'ect separation or said liquid from the solid constituents of the worked material.

3. A device for expressing liquid from liquidthe depth oi the profiled space between the threads of the central worrn' being greater than the height of'the threads or the intermeshing part or the outer worms, a fixed member mounted Q in each of the circumferential spaces between each pair of adjacent outer worms, each such fixed member being spaced from the other such fixedmembers and slidably engaging peripheral portions of the central worm and of a pairoi' adiacent outer worms, inlet means at one end of the central worm for admitting material into the recessed peripheral portion of saidfcentral worm, and outlet means at the other end of said central worm, said fixed members and outer worms cooperating with said central worm to form enclosed spaces in which the worked ma-- terial is carried and compressed by the rotation of said worms, the working clearance between adjacent surfaces of said worms and members being arranged to provide restricted passages through which expressed liquid may pass outwardly from said spaces to eiIect separation oi said liquid from the solid constituents of th worked material.

5. A device forflexpressing liquid from liquidcontaining plastic material, comprising a central 7 rotatable threaded worm, a plurality of rotatable,

threaded, outer worms parallel and inter-meshing with said central worm and circumferentially containing plastic material, comprising a central rotatable threaded worm, a plurality of rotatable, threaded, outer worms parallel and intermeshing with said central worm and circumferentially spaced from one another about said central worm, the number of threads and the diameter of the central worm each being a multiple by a whole number of the number of threads and the diameter, respectively, of one of the outer worms, a fixed member mounted in each of the circumferential spaces between each pair of adjacent outer worms, each such fixed member being spaced from the other such fixed members and slidably engaging peripheral portions of the central worm-and of a pair of adjacent outer .worms, inlet means at one end of the central worm for admitting material into the recessed peripheral portion of said central worm, and outlet means at the other end of said central worm,

- ing clearance between adjacent surfaces of said worms and members being arranged to provide restricted passages through which expressed liqpass outwardly from said spaces to effect sepathe central worm andof a pair of adjacent outer uid may pass outwardly from said spaces to effect separation of said liquid from the solid constituents of the worked material.

4. A device for expressing liquid from liquidcontaining plastic material, comprising a central rotatable threaded worm, a plurality of rotatable,

threaded, outer worms parallel and intermeshing spaced from one another about said central worm. the threads of the central worm widening from the inlet to the outlet end, those of the outer worms narrowing from the inlet to the outlet end, a fixed member mounted in each of the circumferential spaces between each pair of adjacent .outer worms, each such fixed member being spaced from the other such fixed members and slidably engaging peripheral portions or the central worm and of a pair of adjacent outer worms. inlet means at one end of the central worm for admitting material into the recessed peripheral portion of said central worm, and outlet means at the other end of said central worm, said fixed members and outer worms cooperating with said central worm to form enclosed spaces in which the worked material is carried and compressed by the rotation of said worms, the working clearance between adjacent surfaces of said worms and members being arranged to provide restricted passages through which expressed liquid may ration of said liquid fromthe .solid constituents oithe worked material.

6. A device for expressing liquid from liquidcontaining plastic material, comprising a central. rotatable threaded worm, a plurality of rotatable, threaded, outer worms parallel and intermeshing with said central worm and circumferentially spaced from one another about said central worm, a fixed member mounted in each of thecircumferential spacesbetween each pair of adjacent outer worms, each such fixed member being spaced from the other such fixed members and slidably engaging peripheral portions .of

worms, a casing surrounding said worms and said fixed members, inlet means at one end of the central worm for admitting material'into the recessed peripheral portion ofsaid central worm, and'outlet means at the other end of said central worm, said fixed members and outer worms cooperating with said central worm to form enclosed spaces in which the worked material is carried and compressed by the rotation of said worms, the working clearance between adjacent surfaces of said worms and members being arranged to provide restricted passages through which expressed liquid may pass outwardly from said spaces to effect separation of said liquid from the solid constituents of the worked material.

7. A device for expressing liquid from liquidcontaining plastic material, comprising a central rotatable threaded worm, a plurality of rotatable, threaded, outer worms parallel and intermeshing with said central worm and circumferentially spaced from one another about said central worm, a fixed member mounted in each of the circumferential spaces between each pair of adjacent outer worms, each such fixed member being spaced from the other such fixed members and slidably engaging peripheral portions of the central worm and of a pair of adjacent outer worms, a casing rigidly connected with said fixed members and surrounding said worms, inlet means at one end of the central worm for admitting material into the recessed peripheral portion of said central worm, and outlet means at the other end of said central worm,.said fixed members and outer worms cooperating with said central worm to form enclosed spaces in which the worked material is carried and compressed by the rotation of said worms, the working clearance between adjacent surfaces of said worms and members being arranged to provide restricted passages through which expressed liquid may pass outwardly from said spaces to effect separation of said liquid from the solid constituents of the worked material.

8. A device for expressing liquid from liquidcontaining plastic material, comprising a central rotatable threaded worm, a plurality of rotatable, threaded, outer worms parallel and intermeshing with said central worm and circumferentially spaced from one another about said central worm, a fixed member mounted in each of the circumferential spaces between each pair of adjacent outer worms, each such fixed member being spaced from the other such fixed members and slidably engaging peripheral portions of the central worm and of a pair of adjacent outer worms, a hoop supporting and embracing said worms, inlet means at one end of the central worm for admitting material into the recessed peripheral portion of said central worm, and outlet means at the other end of said central worm, said fixed members and outer worms cooperating with said central worm to form enclosed spaces in which the worked material is carried and compressed by the rotation of said worms, the working clearance between adjacent surfaces of said worms and members being arranged to provide restricted passages through which expressed liquid may pass outwardly from said spaces to effect separation of said liquid from the solid constituents of the worked material.

9. A device for expressing liquid from liquidcontaining plastic material, comprising a central rotatable threaded worm, a plurality of rotatable, threaded, outer worms parallel and intermeshing with said central worm and circumferentially spaced from one another about said central worm, the depth of the profiled space between the threads of the central worm being greater than the height of the threads of the intermeshing part of the outer worms, a fixed member mounted in each of the circumferential spaces between each pair of adjacent outer worms, each such fixed member being spaced from the other such fixed members and slidably engaging peripheral portions of the central worm and of a pair of adjacent outer worms, said worms being rotatably mounted on supports rigidly connected with said fixed members, inlet means at one end of the central worm for admitting material into the recessed peripheral portion of said central worm, and outlet means at the other end of said central worm, said fixed members and outer worms cooperating with said central worm to form enclosed spaces in which the worked material is carried and compressed by the rotation of said worms, the working clearance between adjacent surfaces of said worms and members being arranged to provide restricted passages through which expressed liquid may pass outwardly from said spaces to effect separation of said liquid from the solid constituents of the worked material.

10. A device for expressing liquid from liquidcontaining plastic material, comprising a central rotatable threaded worm, a plurality of rotatable, threaded, outer worms parallel and intermeshing with said central worm and circumferentially spaced from one another about said central worm, the threads of the central worm widening from the inlet to the outlet end, those of the outer worms narrowing from the inlet to the outlet end, a fixed member mounted in each of the circumferential spaces between each pair of adjacent outer worms, each such fixed member being spaced from the other such fixed members and slidably engaging peripheral portions of the central worm and of a pair of adjacent outer worms, said worms being rotatably mounted on supports rigidly connected with said fixed members, inlet means at one end of the central worm for admitting material into the recessed peripheral portion of said central worm, and outlet means at the other end of said central worm, said fixed members and outer worms cooperating with said central worm to form enclosed spaces in which the worked material is carried and compressed by the rotation of said worms, the working clearance between adjacent surfaces of said worms and members being arranged to provide restricted passages through which expressed liquid may pass outwardly from said spaces to effect separation of said liquid from the solid constituents of the worked material.

11. A device for expressing liquid from liquidcontaining plastic material, comprising a central rotatable threaded worm, a plurality of rotatable, threaded, outer worms parallel and intermeshing with said central worm and circumferentially spaced from one another about said central worm, a fixed member mounted in each of the circumferential spaces between each pair of adjacent outer worms, each such fixed member being spaced from the other such fixed members and slidably engaging peripheral portions of the central worm and of a pair of adjacent outer worms, said worms being rotatably mounted on supports rigidly connected with said fixed members, a casing surrounding said worms and said fixed members, inlet means at one end of the central worm for admitting material into the recessed peripheral portion of said central worm, and outlet means at the other end of said central worm, said fixed members and outer worms cooperating with said central worm to form enclosed spaces in which the worked material is carried and compressed by the rotation of said worms, the working clearance between adjacent surfaces of said worms and members being arranged to provide restricted passages through which expressed liquid may pass outwardly from said spaces to effect separation of said liquid from the solid constituents of the worked material.

12. A device for expressing liquid from liquidcontaining plastic material, comprising a central rotatable threaded worm, a plurality of rotatable, threaded, outer worms parallel and intermeshing with said central worm and circumferentially spaced from one another about said central worm, the depth of the profiled space between the threads of the central worm being greater than the height of the threads of the intermeshing part of the outer worms, a fixed member mounted in each of the circumferential spaces between each pair of adjacent outer worms, each such fixed member being spaced from the other such fixed members and slidably engaging peripheral portions of the central worm and Of a pair of adjacent outer Worms, a casing surrounding said worms and said fixed members, inlet means at one end of the central worm for admitting material into the recessed peripheral portion of said central worm, and outlet means provided with an adjustable throttling device at the other end of said central worm, said fixed members and outer worms cooperating with said central worm to form enclosed spaces in which the worked material is carried and compressed by the rotation of said spaces to effect separation of said liquid from the solid constituents of the worked material.

13. A device for expressing liquid from liquidcontaining plastic material, comprising a central rotatable threaded worm, a plurality of rotatable. threaded, outer worms parallel and'intermeshing with said central worm and circumferentially spaced from one another about said central worm, the threads of the central worm widening from the inlet to the outlet end, those of the outer worms narrowing from the inlet to the outlet end, a fixed member mounted in each of the circumferential spaces between each pair of adjacent outer worms, each such fixed member being spaced from the other such fixed members and slidably engaging peripheral portions of the central worm and of a pair of adjacent outer worms, a casing surrounding said worms and said fixed members, inlet means at one end of the central worm for admitting material into the recessed peripheral portion of said central worm, and outlet means provided with an adjustable throttling device at the other end of said central worm, said fixed members and outer worms cooperating with said central worm to form enclosed spaces in which the worked material is carried and compressed by the rotation of said worms, the working clearance between adjacent surfaces of said worms and members being arranged to provide restricted passages through which expressed liquid may pass outwardly from said spaces to effect separation of said liquid from the solid constituents of the worked material.

a such fixed member being spaced from the other such fixed members and slidably engaging peripheral portions of the central worm and of a pair of adjacent outer worms, a hoop supporting and embracing said worms, inlet means at one end of the central worm for admitting material into the recessed peripheral portion of said central worm, and outlet means provided with an adjustable throttling device at the other end of said central worm, said fixed members and outer worms cooperating with said central worm to form enclosed spaces in which the worked mate rial is carried and compressed by the rotation of said worms, the working clearance between adjacent surfaces of said worms and members .being arranged to provide restricted passages through which expressed liquid may pass outwardly from said spaces to effect separation of said liquid from the solid constituents of the worked material.

15. A device for expressing liquid from liquidcontaining plastic material, comprising a central rotatable threaded worm, a plurality of rotatable, threaded, outer worms parallel and intermeshing with said central worm and circumferentially spaced from one another about said central worm, the threads of the central worm widening from the inlet to the outlet end, those of the outer worms narrowing from the inlet to the outlet end, a fixed member mounted in each of the circumferential spaces between each pair of adjacent outer worms, each such fixed member being spaced from the other such fixed members and slidably engaging peripheral portions of the central worm and of a pair of adjacent outer worms, a hoop supporting and embracing said worms, inlet means at one end of the central worm for admitting material into the recessed peripheral portion of said central worm, and out- SIEGFRIED KIESSKALT. KARL WINNACKER. KARL ERB. 

